Optical apparatus for the examination of goffered films



Oct. 17, 1933. l. KlTRosER 1,931,228

OPTICAL APPARATUS FOR THE EXAMINATION OF GOFFERED FILMS Filed oct. 13,1930 INVENTOR ATTORNEY .Tiili *E Tllwlllw Patented oct. 17, 1933 i1,931,228

OPTICAL APPARATUS FOR THE EXAMINA- TION OF GOFFERED FILMS IsaacKitroser, Paris, France, assigner to Keller- Dorian Colorlm Corporation,New York, N. Y., a. corporation of Delaware Application October 13,1930. Serial No. 488,306

7 Claims. (Cl. 88-39) My invention relates especially to a specialSeveral means of adjustment should be prooptical magnifying glass forthe examination of vided for, however.

goiered colored films. First, the regulation of the magnifying glass Theobject of the present invention is to pro- 6 for different observers,that is to say normalvide special magnifying glasses enabling gofferedsighted, short-sighted and far-sighted. 60

films to be examined more effectively. SeCOIldly. the light ltel 2 mustbe able C0 b While my invention is capable of embodiment set correctlyin reference to the cylindrical lenses in many different forms, theannexed drawing of the goffering. illustrates the optical system madeaccording to Thirdly, the same light filter 2 must be able to 10 myinvention, in which Figure 1 shows diagrammove forwardly or backwardlywith regard to 65 matically the path of the luminous rays enablingfocal-plane of the lens 3 in order to rectify the one to see thecinematographic picture in its displacement of the magnifying glass 6.proper size and its natural colors with the aid of The following aresome mathematical formula: the color filter, and Figure 2 shows themounting which may be used in order to determine the optiof the lenses,in the example where a collimating cal characteristics of the presentapparatus. 7o lens is used. j is the focus of the lens 3, that is to saythe Referring to the drawing, I have shown a planodistance between saidlens and the three-color convex lens I, which has a flat side with afilter 2.

ground glass finish and a very much bulged con- The magnifying power ofthe vex side in order to make this lens a perfect lu- 250 75 minousdiffuser. This lens which is in contact apparatus=mm.,

with the three-color light lter 2, for example a filter having 3 bandscolored blue, green and red Where, F=f0011S 0f the 1611585 6 and 5-respectively, illuminates it uniformly. 1 1 1 E The three-color filter 2is exactly in the focal -:-l'- 80 l 2 1 2 plane of a colhmatric lens 3which directs the Where light in parallel rays on to the film to beviewed.

The ratio of the diameter of the light filter 2 1=fOC11S 01'16115 6. tothe focal length of the lens 3 is the same as f2=f00l1S 0116115 5, andthe aperture of the camera photographic objec- E=dstance' between thelens 6 and 1BRS 5- 85 tive, that is to say in the camera used in takingthe pictures on the film, the size of the pupil of glfilxlrais ggre themm has been taken with a emergence or apparent size of the diaphragm I 11 1 seen from the focal plane of the camera lens divided by the focallength of the lens. e lf2-E fl 90 On the other hand, the width of thecentral where, ezdistance between the pupil of the eye strip, forexample the green strip, of the threeand the lens 6. color lter 2 shouldbe 0,264 times the diameter For instance, Figures 1 and 2 show amagnifyof the opening in the filter, in order that the ing glass ofmagnifying power 4, and a0 green surface may be equal to the adjoiningspaces 95 which are red or blue. Consequently, there will =f+lbe nocolor having more light receiving area than l l another and the samerule must be adopted for where K is the distance between the lens 5 andthe light lter of the camera objective. the film 4.

A goirered nlm 4 carrying the picture is ar- The magnifying power of theapparatus is 10o ranged to slide between the lens 3 and a lens 5,therefore the goifered face being turned towards the filter 250 2. Thecylindrical lenses of the lenticulated sur- 4'" F face of the gofferedlm are arranged parallel to the Strips of C0101, in the lter. As anexample, the characteristics of a set of The lens 5 which can be calleda eld lens has lenses whlch may be used m my apparatus would for itsobject to form the image of the alter 2 aooolllllgly loo as lollowsl onthe pupil of the observers eye 7. Finally, a F=62.5 mm. E=62 mm. lens 6is provided as a magnifying glass of conf1=65 mm. e =10.8 mm.

5 venient magnifying power. f2=75 mm. K= 2.89 mm. 110

If the film has not been taken with a collimating lens, ,the lens 3would not be used at all or would not be a collimating lens, but ifused, must have such a focus that the filter as seen through it, or thevirtual image, should appear to be at the same distance from the film asthe color filter virtual image.' appears to be from the film in thecamera objective; and the lens 5 must be chosen so as to form the imageof the filter 2 on the observers pupil. For such a lens 5,

where, /1=focus of lens 3, f is the distance between the lens 3 and thecolor lter 2, and a=dis tance of the color filter to the film in cameraobjective.

l SIZ 1 O {2&Ea-{FEf2 f1 For example, lenses used in my apparatus forviewing a film not taken with a collimated lens, could have thefollowing characteristics:

F== 62.5 mm. la: 35 mm. f: I5 mm. E= 65.8 mm. a= 50 mm. K: 3.75 mm.f1=-150 mm. e: 14.57 mm.

As shown in Fig. 2, the lenses, as above referred to, may be mounted asfollows: The diffuser 1 and color filter 2 in the form of two glassplates with 3 color bands between them may be mounted in the end of anouter sleeve 8 arranged to slide back and forth on one end of a tube 9.A screwthreaded ring 10 and a friction-retained diaphragm 11, hold thediffuser l and the color filter 2 in place. In the other end of the tube9 there is screw-threaded a flanged ring 12 for receiving lthecollimating lens 3. an inner screw-threaded ring 13 being provided as aretainer for said lens. To the flanged ring 12 there is screwed asimilar flanged ring 14, provided for holding the lens 5, a retainerring 15 being located therein adjacent to the said lens 5. The rings 12and 14 have a slot 15'* between them for receiving the film 4 to beviewed. A sleeve 16 is screw-threaded to the ring 14, and within thesleeve 16 there is a tube 1'?, arranged to be moved back and forth, tothe forward end of which there is screw-threaded a flanged ring 18, towhich there is screw-threaded in turn an eye-piece 19 for retaining inplace the lens 6.

In use, the film 4 is inserted in the slot 15a, with the golferingfacing the color filter 2 with the pictures upright, and the sleeve 8 isturned until the color bands of the filter 2 are in the oppositeposition to those of the color filter in the camera lens used where anoriginal film is being viewed in the apparatus, and with the color bandsof the filter 2 in the same position as those in the camera color filterwhere a copy of the original film is being viewed. The sleeve 8 is thenmoved back and forth until the color filter 2 is seen with the eye, andthen the tube 17 is moved back and forth until the pictures appear sharpto the eye, when the pictures will appear in the original colors of theobjects viewed therein.

While I have described my invention above in detail, it is to beunderstood that many changes may be made therein without departing fromthe spirit thereof.

I claim:

1. A magnifying glass for examining a goffered film,` comprising anoptical means, including a color filter, adapted to apply color areas oflight to the goffered film, corresponding to the color areas throughwhich the picture was taken thereon, including a light diffuser and acollimating lens, the filter being located in the focal plane of thecollimating lens, and a magnifying device adapted for viewing the filmwith the aid of the color areas applied thereto.

2. A magnifying glass for examining a goffered film, comprising anoptical means, including a color filter, adapted to apply color areas oflight to the goffered film, corresponding to the color areas throughwhich the picture was taken thereon, including a light diffuser and acollimating lens, the filter being located in the focal plane of thecollimating lens, and a magnifying device adapted for viewing the filmwith the aid of the color areas applied thereto comprising a field lensadapted to form an image of the color filter on the pupil of the eye.

3. A magnifying glass for examining a goffered film, comprising anoptical means, including a color filter, adapted to apply color areas oflight to the goffered film, corresponding to the color areas throughwhich the picture was taken there- 105 on, including a light diffuserand a collimating lens, the filter being located in the focal plane ofthe collimating lens, and a magnifying device adapted for viewing thefilm with the aid of the color areas applied thereto comprising a field110 lens adapted to form an image of the color filter on the pupil ofthe eye; and a magnifying lens adapted for enabling the image to be seennear to the observer.

4. A magnifying glass for examining a goffered 115 film, comprising anoptical means, including a color filter, adapted to apply color areas oflight to the goffered lm, corresponding to the color areas through whichthe picture was taken thereon, including a light diffuser and acollimating lens, the filter being located in the focal plane of thecollimating lens, and a magnifying device adapted for viewing the fllmwith the aid of the color areas applied thereto comprising a field lensadapted to form an image of the color filter on the pupil of the eye;and a magnifying lens adapted for enabling the image to be seen near tothe observer, the color filter and magnifying lens being so mounted asto be capable of adjustment to and from the film respectively.

5. A magnifying glass for examining a goffered film, comprising anoptical means, including a color filter, adapted to apply color areasof.' light to thegoifered film, corresponding to the color areas throughwhich the picture was taken thereon, including a light diffuser and acollimating lens, the filter being located in the focal plane of thecollimating lens, and a magnifying device adapted for viewing the filmwith the aid of the color areas applied thereto, the ratio of thediameter of the color filter to the focal length of the collimating lensbeing the same as the aperture of the camera with which the film picturewas made.

6. A magnifying glass for examining a goffered film, comprising anoptical means, including a color filter and a lens, adapted to applycolor areas of light to the goffered film, corresponding to the colorareas through which the picture was taken thereon, and a magnifyingdevice to the goiered film, corresponding to the color areas throughwhich the picture was taken thereon, and a magnifying 'device adaptedfor viewing the film with the aid of the color areas applied thereto,the color lter being located the same distance from the film, when thelatter was not taken with a collimating lens, as the lm was from thevirtual image of the color filter in the camera lens.

ISAAC KITROSER.

